Against all odds, Burton held United to an FA Cup draw in January 2006, earning a replay at Old Trafford and a windfall of around £800,000, which altered the future for the then non-league side.
Burton were able to pay off the overspend on the newly built Pirelli Stadium as well as invest in a playing squad that has since risen remarkably.
"Getting the replay is singularly the most important development in the rise of the club," said Clough. "We needed a new stadium, but it was a big risk. It went over budget and we got Man United at the absolute perfect time.
"The initial game wouldn't have been enough. It was the replay that made the difference and we've been debt-free ever since."